Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Xanthorrhizol is a sesquiterpenoid compound extracted from the rhizome of Curcuma xanthorrhiza. This study investigated the antiproliferative effect and the mechanism of action of xanthorrhizol on human hepatoma cells, HepG2, and the mode of cell death. An antiproliferative assay using methylene blue staining revealed that xanthorrhizol inhibited the proliferation of the HepG2 cells with a 50% inhibition of cell growth (IC50) value of 4.17 +/- 0.053 microg/ml. The antiproliferative activity of xanthorrhizol was due to apoptosis induced in the HepG2 cells and not necrosis, which was confirmed by the Tdt-mediated dUTP nick end labeling (TUNEL) assay. The xanthorrhizol-treated HepG2 cells showed typical apoptotic morphology such as DNA fragmentation, cell shrinkage and elongated lamellipodia. The apoptosis mediated by xanthorrhizol in the HepG2 cells was associated with the activation of tumor suppressor p53 and down-regulation of antiapoptotic Bcl-2 protein expression, but not Bax. The levels of Bcl-2 protein expression decreased 24-h after treatment with xanthorrhizol and remained lower than controls throughout the experiment, resulting in a shift in the Bax to Bcl-2 ratio thus favouring apoptosis. The processing of the initiator procaspase-9 was detected. Caspase-3 was also found to be activated, but not caspase-7. Xanthorrhizol exerts antiproliferative effects on HepG2 cells by inducing apoptosis via the mitochondrial pathway.
 ...
PMID:Regulation of p53-, Bcl-2- and caspase-dependent signaling pathway in xanthorrhizol-induced apoptosis of HepG2 hepatoma cells. 1746 28

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively kill tumor cells and, in combination with other agents, could enhance tumor therapy. We explored the combined therapeutic effects of a secretable form of (S) TRAIL-induced apoptosis and the downregulation of Bcl-2 in human gliomas. We constructed a lentiviral delivery system: 1) for the expression of short hairpin (sh) RNA to downregulate Bcl-2 and for the expression of S-TRAIL to induce apoptosis in glioma cells; and 2) to follow delivery in vitro and the fate of tumors in real time in vivo. We demonstrate that lentiviral-mediated simultaneous downregulation of Bcl-2 and S-TRAIL-induced apoptosis leads to an increased expression of activated caspase-3 and caspase-7, thus resulting in accelerated S-TRAIL-mediated apoptosis in glioma cells in vitro. Using a highly malignant human glioma model expressing EGFRvIII and firefly luciferase, we show that the combined effect of Bcl-2 downregulation and S-TRAIL-induced apoptosis results in complete eradication of gliomas compared to S-TRAIL monotherapy. These results show that simultaneous triggering of TRAIL-mediated death receptor pathway and downregulation of Bcl-2 by shRNA leads to enhanced eradication of gliomas and serves as a template in developing and monitoring combination therapies for the treatment of drug-resistant cancers.
 ...
PMID:Tumor therapy mediated by lentiviral expression of shBcl-2 and S-TRAIL. 1753 49

Oligonol is a novel catechin-rich biotechnology product. The role of oligonol in modulating intracellular signaling mechanisms was investigated with the view of demonstrating its potential chemopreventive effect and the ability to inhibit cell proliferation using the estrogen-responsive MCF-7 and the estrogen-unresponsive MDA-MB-231 human breast cancer cell lines. Cell survival assay indicated that Oligonol was cytotoxic to both cells. Oligonol triggered apoptosis as revealed by the morphological features typical of nucleus staining and the accumulation of sub-G1 peak. Treatment with 25 microg/ml Oligonol resulted in an activation of caspase-7 and up-regulation of Bad on MCF-7 cells, while the Oligonol (20 microg/ml) induced up-regulation of Bcl-2 protein in a time-response manner on MDA-MB-231 cells. ERK1/2 in both cells were inactivated after Oligonol treatment in a time-dependent manner, and also inactivated upstream MEK1/2. Oligonol triggers apoptosis in MCF-7 and MDA-MB-231 cells through the modulation of pro-apoptotic Bcl-2 family proteins and MEK/ERK signaling pathway.
 ...
PMID:Induction of apoptosis in MCF-7 and MDA-MB-231 breast cancer cells by Oligonol is mediated by Bcl-2 family regulation and MEK/ERK signaling. 1755 7

A novel bioactive polyacetylene compound, 1,2-dihydroxy-5(E)-tridecene-7,9,11-triyne (compound 1), was identified from the Bidens pilosa extract using an ex vivo primary human umbilical vein endothelium cell (HUVEC) bioassay-guided fractionation protocol. Our results demonstrate that compound 1 (at 2.5 microg/mL) possessed significant anti-angiogenic effects, as manifested by an inhibition of HUVEC proliferation, migration, and the formation of tube-like structures in collagen gel. Moreover, compound 1 induced HUVECs to undergo cell death in a concentration- and time-dependent manner. The mechanisms underlying these pharmacological effects include reduced expression of cell cycle mediators such as CDK4, cyclins D1 and A, retinoblastoma (Rb) and vascular endothelial growth factor receptor 1 (VEGFR-1), and promotion of caspase-mediated activation of CDK inhibitors p21(Cip1) and p27(Kip). Moreover, apoptotic induction in HUVECs mediated by compound 1 was found to be in part through overexpression of FasL protein, down-regulation of anti-apoptotic Bcl-2, and activation of caspase-7 and poly(ADP-ribose) polymerase. This study demonstrates the potent anti-angiogenic and apoptotic activities of compound 1, suggesting that phytocompounds such as polyacetylenes deserve more attention regarding their potential as candidates for anti-angiogenic therapeutics.
 ...
PMID:A novel polyacetylene significantly inhibits angiogenesis and promotes apoptosis in human endothelial cells through activation of the CDK inhibitors and caspase-7. 1755 25

Bim is a proapoptotic BH3-domain-only member of the Bcl-2 family, and its expression is regulated both transcriptionally and posttranslationally. We developed an in vitro system examining the posttranslational regulation of Bim. Since Bim is a strong mediator of apoptosis, it has been quite difficult to establish cell lines stably overexpressing Bim. Coexpression of Bcl-2 enabled us to obtain mouse embryonic fibroblasts (MEFs) in which Bim is overexpressed and Bcl-2 expression is regulated by Tet-off system. Reduction of Bcl-2 levels by doxycycline treatment induced caspase-3 and caspase-7 activation, which was followed by Bim degradation. Bim degradation was suppressed by gene knockdown of caspase-3, but not by caspase-7 knockdown. The same posttranslational regulation of Bim was observed in osteoclasts. These results suggest that caspase-3 negatively regulates Bim expression by stimulating its degradation, thus creating a negative feedback loop in the Bim-caspase axis.
 ...
PMID:Posttranslational regulation of Bim by caspase-3. 1758 89

The mechanism of acacetin-induced apoptosis of human breast cancer MCF-7 cells was investigated. Acacetin caused 50% growth inhibition (IC50) of MCF-7 cells at 26.4% 0.7% M over 24 h in the MTT assay. Apoptosis was characterized by DNA fragmentation and an increase of sub-G1 cells and involved activation of caspase-7 and PARP (poly-ADP-ribose polymerase). Maximum caspase 7 activity was observed with 100 microM acacetin for 24 h. Caspase 8 and 9 activation cascades mediated the activation of caspase 7. Acacetin caused a reduction of Bcl-2 expression leading to an increase of the Bax:Bcl-2 ratio. It also caused a loss of mitochondrial membrane potential that induced release of cytochrome c and apoptosis inducing factor (AIF) into the cytoplasm, enhancing ROS generation and subsequently resulting in apoptosis. Pretreatment of cells with N-acetylcysteine (NAC) reduced ROS generation and cell growth inhibition, and pretreatment with NAC or a caspase 8 inhibitor (Z-IETD-FMK) inhibited the acacetin-induced loss of mitochondrial membrane potential and release of cytochrome c and AIF. Stress-activated protein kinase/c-Jun NH4-terminal kinase 1/2 (SAPK/ JNK1/2) and c-Jun were activated by acacetin but extracellular-regulated kinase 1/2 (Erk1/2) nor p38 mitogen-activated protein kinase (MAPK) were not. Our results show that acacetin-induced apoptosis of MCF-7 cells is mediated by caspase activation cascades, ROS generation, mitochondria-mediated cell death signaling and the SAPK/JNK1/2-c-Jun signaling pathway, activated by acacetin-induced ROS generation.
 ...
PMID:Acacetin-induced apoptosis of human breast cancer MCF-7 cells involves caspase cascade, mitochondria-mediated death signaling and SAPK/JNK1/2-c-Jun activation. 1784 3

Previously, the expression of caspase-3 siRNA could not effectively inhibit sodium butyrate (NaBu)-induced apoptotic cell death of recombinant Chinese hamster ovary (rCHO) cells producing human thrombopoietin (hTPO). Caspase-3 siRNA expressing cells appeared to compensate for the lack of caspase-3 by increasing active caspase-7 levels. For the successful inhibition of NaBu-induced apoptosis of rCHO cells, both caspase-3 and caspase-7 were down-regulated using the siRNA expression vector system. Co-down-regulation of caspase-3 and caspase-7 increased cell viability and extended culture longevity in serum-free culture in the presence or absence of 1mM NaBu addition. In the cultures with 1mM NaBu addition, the maximum hTPO concentration in rCHO cells with down-regulation of both caspases was approximately 55% higher than that in rCHO cells without down-regulation of caspases and approximately 16% higher than rCHO cells with down-regulation of only caspase-3. However, in the culture with 3mM NaBu, this strategy could not dramatically enhance the culture longevity and hTPO production, compared to Bcl-2 overexpression. The different result in hTPO production between down-regulation of caspases and Bcl-2 overexpression may be because the down-regulation of caspase-3 and caspase-7, unlike Bcl-2 overexpression, could not maintain mitochondrial membrane potential in the presence of 3mM NaBu. Taken together, co-down-regulation of caspase-3 and caspase-7 is effective in regard to extension of culture longevity and enhancement of hTPO production in a serum-free culture in the presence or absence of 1mM NaBu addition.
 ...
PMID:Influence of co-down-regulation of caspase-3 and caspase-7 by siRNAs on sodium butyrate-induced apoptotic cell death of Chinese hamster ovary cells producing thrombopoietin. 1789 62

(1) Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by the expansion of polymorphic CAG repeats beyond 36 at exon 1 of huntingtin gene (htt). To study cellular effects by expressing N-terminal domain of Huntingtin (Htt) in specific cell lines, we expressed exon 1 of htt that codes for 40 glutamines (40Q) and 16Q in Neuro2A and HeLa cells. (2) Aggregates and various apoptotic markers were detected at various time points after transfection. In addition, we checked the alterations of expressions of few apoptotic genes by RT-PCR. (3) Cells expressing exon 1 of htt coding 40Q at a stretch exhibited nuclear and cytoplasmic aggregates, increased caspase-1, caspase-2, caspase-8, caspase-9/6, and calpain activations, release of cytochrome c and AIF from mitochondria in a time-dependent manner. Truncation of Bid was increased, while the activity of mitochondrial complex II was decreased in such cells. These changes were significantly higher in cells expressing N-terminal Htt with 40Q than that obtained in cells expressing N-terminal Htt with 16Q. Expressions of caspase-1, caspase-2, caspase-3, caspase-7, and caspase-8 were increased while expression of Bcl-2 was decreased in cells expressing mutated Htt-exon 1. (4) Results presented in this communication showed that expression of mutated Htt-exon 1 could mimic the cellular phenotypes observed in Huntington's disease and this cell model can be used for screening the agents that would interfere with the apoptotic pathway and aggregate formation.
 ...
PMID:Increased caspase-2, calpain activations and decreased mitochondrial complex II activity in cells expressing exogenous huntingtin exon 1 containing CAG repeat in the pathogenic range. 1790 43

Clinical outcome in patients with primary nodal diffuse large B-cell lymphomas (DLBCLs) is correlated with expression of inhibitors of the intrinsic apoptosis pathway, including X-linked inhibitor of apoptosis protein (XIAP). XIAP suppresses apoptosis through inhibiting active caspase-3, caspase-7, and caspase-9. In this study, we investigated to see if the small-molecule XIAP antagonist 1396-12 induces cell death in cultured lymphoma cells of patients with DLBCL. Treatment with this XIAP antagonist resulted in relief of caspase-3 inhibition and in induction of apoptosis in 16 of 20 tested DLBCL samples. Sensitivity to the XIAP antagonist was observed in both chemotherapy-refractory and -responsive DLBCL, but did not affect peripheral blood mononuclear cells and tonsil germinal-center B cells from healthy donors. XIAP antagonist-sensitive samples were characterized by high expression levels of XIAP, relatively low expression levels of Bcl-2, and by constitutive caspase-9 activation. These data indicate that the small-molecule XIAP antagonist can induce apoptosis in cultured DLBCL cells and therefore should be considered for possible development as a therapy for these patients. In vitro sensitivity to the XIAP antagonist can be predicted based on biological markers, suggesting the possibility of predefining patients most likely to benefit from XIAP antagonist therapy.
 ...
PMID:Small-molecule XIAP antagonist restores caspase-9 mediated apoptosis in XIAP-positive diffuse large B-cell lymphoma cells. 1791 49

F16 is a plant-derived pharmacologically active fraction extracted from Eurycoma longifolia Jack. Previously, we have reported that F16 inhibited the proliferation of MCF-7 human breast cancer cells by inducing apoptotic cell death while having some degree of cytoselectivity on a normal human breast cell line, MCF-10A. In this study, we attempted to further elucidate the mode of action of F16. We found that the intrinsic apoptotic pathway was invoked, with the reduction of Bcl-2 protein. Then, executioner caspase-7 was cleaved and activated in response to F16 treatment. Furthermore, apoptosis in the MCF- 7 cells was accompanied by the specific proteolytic cleavage of poly(ADP-ribose) polymerase-1 (PARP-1). Surprisingly, caspase-9 and p53 were unchanged with F16 treatment. We believe that the F16-induced apoptosis in MCF-7 cells occurs independently of caspase-9 and p53. Taken together, these results suggest that F16 from E. longifolia exerts anti-proliferative action and growth inhibition on MCF-7 cells through apoptosis induction and that it may have anticancer properties.
 ...
PMID:F16, a fraction from Eurycoma longifolia jack extract, induces apoptosis via a caspase-9-independent manner in MCF-7 cells. 1797 90


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>